Recent investigations in our laboratory revealed that short-term alcohol consumption by lactating women imparts a distinctive odor to their milk, and alters mother-infant interaction during breast feeding. NM intake was diminished and the patterning of sucking was altered during the three hours that followed maternal alcohol consumption. Additionally, the infants slept more frequently, but for shorter periods of time during the day their mothers consumed the alcoholic beverage. The studies proposed herein will determine the mechanism or mechanisms underlying these changes in the infant's behaviors, with a practical aim of providing information on a much neglected area in scientific research. First, alcohol may affect lactational performance. Thus, we propose studies to determine whether acute alcohol consumption alters the composition, yield, flow, and caloric content of human milk (AIM 1). Second, the change in the flavor of the milk may influence the infant's feeding behavior. Psychophysical methodologies will be employed to determine in what way the transfer of alcohol alters the flavor of human milk (AIM 2), and the infant's suckling and intake patterns while drinking alcohol-flavored mother's milk from a bottle will be established (AIM 3). Third, alcohol may have direct effects on the breast-feeding infant. Studies are planned to determine whether exposure to alcohol in mother's milk affects motor activity, sleep architecture, and a variety of other ongoing behaviors, as well as mother-infant interaction (AIM 4). And because non-human animal studies reveal that early exposure to the flavor of alcohol affects later preferences, we will also determine whether alcohol exposure via mother's milk affects the human infant's responsiveness to the sensory qualities of alcohol in other contexts (AIM 5). These studies will lay the foundation for future work on the effects of alcohol on human lactation, and the role of the chemical senses in the development of preferences for alcohol.